build: asdf-build-system: Make sbcl-* Lisp packages reproducible.

The '*.fasl' files produced by SBCL contain the mtime of the source file (see
commit 72843d7ce32bd615f64a0326cf891658b5724ead of SBCL's code repository).
As asdf-build-system makes a copy of the source files before compiling them,
we must set the mtime of these copies to the same date as the originals for
the build to be reproducible.

* guix/build/asdf-build-system.scm (copy-files-to-output): Keep the
  modification time of the original source files.

diff --git a/guix/build/asdf-build-system.scm b/guix/build/asdf-build-system.scm
index dd6373b..1be2b3c 100644 (file)
--- a/guix/build/asdf-build-system.scm
+++ b/guix/build/asdf-build-system.scm
@@ -79,7 +79,7 @@ valid."
   (let ((source (getcwd))
         (target (source-directory out name))
         (system-path (string-append out %system-install-prefix)))
-    (copy-recursively source target)
+    (copy-recursively source target #:keep-mtime? #t)
     (mkdir-p system-path)
     (for-each
      (lambda (file)